gdb/fortran: Handle internal function calls

If an convenience function is defined in python (or guile), then
currently this will not work in Fortran, instead the user is given
this message:

  (gdb) set language fortran
  (gdb) p $myfunc (3)
  Cannot perform substring on this type

Compare this to C:

  (gdb) set language c
  (gdb) p $myfunc (3)
  $1 = 1

After this patch we see the same behaviour in both C and Fortran.
I've extended the test to check that all languages can call the
convenience functions - only Fortran was broken.

When calling convenience functions in Fortran we don't need to perform
the same value preparation (passing by pointer) that we would for
calling a native function - passing the real value is fine.

gdb/ChangeLog:

	* eval.c (evaluate_subexp_standard): Handle internal functions
	during Fortran function call handling.

gdb/testsuite/ChangeLog:

	* gdb.python/py-function.exp: Check calling helper function from
	all languages.
	* lib/gdb.exp (gdb_supported_languages): New proc.

1 files changed, 8 insertions, 4 deletions

diff --git a/gdb/eval.c b/gdb/eval.c
index 9d8eb34..3f768b4 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1979,6 +1979,7 @@ evaluate_subexp_standard (struct type *expect_type,
 
 	case TYPE_CODE_PTR:
 	case TYPE_CODE_FUNC:
+	case TYPE_CODE_INTERNAL_FUNCTION:
 	  /* It's a function call.  */
 	  /* Allocate arg vector, including space for the function to be
 	     called in argvec[0] and a terminating NULL.  */
@@ -1996,10 +1997,13 @@ evaluate_subexp_standard (struct type *expect_type,
 		 results in malloc being called with a pointer to an integer
 		 followed by an attempt to malloc the arguments to malloc in
 		 target memory.  Infinite recursion ensues.  */
-	      bool is_artificial =
-		TYPE_FIELD_ARTIFICIAL (value_type (arg1), tem - 1);
-	      argvec[tem] = fortran_argument_convert (argvec[tem],
-						      is_artificial);
+	      if (code == TYPE_CODE_PTR || code == TYPE_CODE_FUNC)
+		{
+		  bool is_artificial
+		    = TYPE_FIELD_ARTIFICIAL (value_type (arg1), tem - 1);
+		  argvec[tem] = fortran_argument_convert (argvec[tem],
+							  is_artificial);
+		}
 	    }
 	  argvec[tem] = 0;	/* signal end of arglist */
 	  if (noside == EVAL_SKIP)